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List of United States television channel allocations
The very high frequency (VHF) band Prior to 1934, no frequencies were specifically for television, but experimental stations were assigned frequencies at various points in the spectrum. Many were high (opposed to "very high") frequencies such as 2.1 MHz. In 1934, frequency bands were set up by the FCC covering 42-46 and 60-86 MHz, but without specific channels assigned. In October 1938, the first tentative channel assignments were made. Nineteen channels were allotted as shown in the table below. However, because the FCC had not yet adopted standards for television broadcasting, hearings were held, and on December 22, 1939, a set of rules was adopted for limited commercial television broadcasting. However, different manufacturers wanted different standards, and it took until February 29, 1940 before FCC rules permitting limited commercialization effective September 1 went into effect. It will be noted that there are gaps between many of the channels, and most of the channels are grouped in pairs of adjacent frequencies (except for channel 3). There are two big blocks, a low band (44-108 MHz) and a high band (156-294 MHz), a forerunner of the eventual system. On June 20, 1940, the 44-50 MHz channel was taken away from television, and assigned to FM broadcasting. Most of the channel numbers were lowered by 1 in consequence of this; some of the gaps were adjusted, so the resulting arrangement was as follows: In April 1941, the FCC finally adopted the 525-line standard and declared that commercial broadcasting would begin July 1. On June 27, 1945, the FCC reduced television's allotment to 13 channels: the gap between the low and high band was widened, and all the channels above 230 MHz were dropped; the 44-50 MHz channel which had been dropped in 1940 was restored, and the gaps between adjacent channels were mostly eliminated; the FM band was moved to its current VHF band (moving the lower numbered channels down again) (See List of United States FM frequency allocations). Thus the new lineup was: On June 14, 1948, channel 1 was taken away, so that the television channels were numbered 2 to 13 with no 1. This became the permanent frequency allocation for the VHF television channels in the United States. The ultrahigh frequency (UHF) band By 1952, it became obvious that twelve channels would not be enough; even the 19 originally envisioned were thought to be insufficient. So seventy additional channels, numbered 14 to 83 as below, were allocated in the ultrahigh frequency part of the spectrum. The first UHF station, KPTV, in Portland, Oregon, went on the air on Channel 27 on September 18, 1952. However, this proved not to solve the problem very well, as most television sets could not receive the UHF channels until the FCC mandated in 1964 that new television sets had to be built with tuners that included the UHF channels. Because the UHF channels never became as popular as had been anticipated, in the 1980s, channels 70-83, which in fact had been reserved for repeaters anyway, were deleted from the television allocations and the frequencies were reassigned to cellular telephone use. On June 12, 2009, in conjunction with the switch from analog to digital television broadcasting, additional channels were deleted; everything from channel 52 up. Channels 70 to 83 were deleted in 1983 by a worldwide convention which reassigned those frequencies to the Land Mobile Radio System (Public Safety and Trunked Radio) and mobile phones. In 2009, television was converted to digital, and channels 52 to 69 were deleted. Category:Frequency allocations